Method for treating a solvent-extracted plant residue with a fat

ABSTRACT

A method of treating solvent-extracted plant residue comprises (a) providing a plant residue of one or more plant parts with a reduced content of plant fats, the fats having been extracted by means of a solvent for said plant fats; (b) mixing said solvent-extracted plant residue with a conditioning fat; and (c) milling said mixture of plant residue and conditioning fat under reduced pressure, said conditioning fat being in a liquid state. If the milling step has taken place at a temperature below about 100° C., the resulting milled compound mixture is subjected to (d) a post heat treatment at temperatures above 100° C. A compound mixture of milled solvent-extracted plant residue and conditioning fat obtainable by the method. Food products and feeds comprising said compound mixture of milled solvent-extracted plant residue and conditioning fat.

1. BACKGROUND OF THE INVENTION

[0001] The present invention relates to a method of treating asolvent-extracted plant residue, a compound mixture of a milledsolvent-extracted plant residue and conditioning fat obtainable by themethod, and food products and feeds comprising the compound mixture.

[0002] The Technical Field

[0003] Generally, when producing vegetable oils and fats, the productionprocess comprises a pressing step that produces a press cake as aby-product. The press cake comprises a plant residue with reduced fatcontent.

[0004] The press cake is often used as an animal feed. However, in theprocessing of cocoa for example, wherein a heating step (roasting)usually precedes the milling and pressing steps, the press cake can bebroken and pulverized into a cocoa powder which is of a microbiologicalquality suited for human consumption.

[0005] Generally, in the production of vegetable oils and fats, solventextraction can be used to increase the yield of recovered oils and fats.However, solvent extraction produces a solvent-extracted plant residue,often referred to as meal, which contains residual solvent and, usually,microbiological activity.

[0006] The meal is normally considered a waste product. In some cases,however, such as in production of soya oil from soya beans, the meal canbe used in the production of animal feed.

[0007] In other cases, for example in production of shea butter, thesolvent-extracted shea residue contains substances unsuitable for feed.Consequently, the meal has to be disposed of e.g. by combustion.

[0008] Some solvent-extracted plant residues have contents of functionalconstituents that can be used in human food. Examples include meal fromcocoa beans containing aroma and color, and meal from flaxseed that is asource of phenolic acids and dietary fibres of which about a third iswater-soluble mucilage.

[0009] Consequently, there is a need for a method for treating asolvent-extracted plant residue to provide a useful product having anacceptably low residual solvent content and low microbiologicalactivity.

[0010] Prior Art Disclosures

[0011] “Bailey's Industrial Oil and Fat Products”, Wiley IntersciencePublication, Vol. 2, Fourth Edition, 1982, especially the section“Mechanical Expression of Oil and Solvent Extraction”, Chapter 3, p.201-245, discloses production of vegetable oils and fats in general.

[0012] Beckett, “Industrial Chocolate Manufacture and Use”, BlackwellScience, Third Edition, 1999, especially the section “Cocoa Mass, CocoaButter and Cocoa Powder”, Chapter 6, p. 101-114, discloses processing ofcocoa.

[0013] DE examined patent application No. 1 692 387 discloses a methodfor production of cocoa-containing fat compound coating wherein crushedcocoa beans of natural humidity are pressed in an expeller press forremoval of cocoa butter. The expelled residue is mixed with a non-cocoafat and sugar in a one step liquid-milling process to produce a paste ofchocolate grade powder. Nothing is mentioned neither about solventextraction of residual cocoa butter of the expelled residue nor aboutany treatment of such solvent-extracted expelled residue.

[0014] U.S. Pat. No. 5,919,502 discloses a process for the production ofa compound liquor which is suitable for making compound coatings andalternatives to chocolates; said process comprising feeding whole rawcocoa beans into an expeller to remove cocoa butter, and extractingresidual cocoa butter by means of an organic solvent to produce asubstantially fat-free cocoa cake. The cocoa cake is pulverized intococoa powder and mixed with a confectionery fat to produce the compoundliquor. Nothing is mentioned neither about mixing the substantiallyfat-free cocoa cake with the confectionery fat before pulverisation ofthe solvent-extracted cocoa cake into a fat containing cocoa powder, norabout wearing problems of milling equipment during milling of wholebeans, or about any treatment to reduce the content of solvent in thecompound liquor, or to provide a microbiological quality of food gradestandard.

DISCLOSURE OF THE INVENTION

[0015] Object of the Invention

[0016] It is an object of the present invention to provide an improvedmethod for treating solvent-extracted plant residues.

[0017] It is another object of the present invention to provide animproved method for such treatment whereby wearing of milling equipmentby presence of soil particles and hard plant parts is reduced.

[0018] It is another object of the present invention to provide animproved method for such treatment whereby the amount of residualsolvent is reduced to an acceptable level for application in foods.

[0019] It is another object of the present invention to provide animproved method for such treatment whereby the microbiological qualityis improved to food grade standard.

[0020] Further objects appear from the description elsewhere.

[0021] Solution According to the Invention

[0022] According to the present invention, these objects are fulfilledby providing a method of treating a solvent-extracted plant residue asdefined in claim 1, the method comprising

[0023] (a) providing a plant residue of one or more plant parts with areduced content of plant fats, the fats having been extracted by meansof a solvent for said plant fats;

[0024] (b) mixing said solvent-extracted plant residue with aconditioning fat;

[0025] (c) milling said mixture of plant residue and conditioning fatunder reduced pressure, said conditioning fat being in a liquid state;and

[0026] (d) if the milling has taken place at a temperature below about100° C., subjecting the resulting compound mixture of milled plantresidue and conditioning fat to a post heat treatment at temperaturesabove about 100° C.

[0027] It has surprisingly turned out that by mixing saidsolvent-extracted plant residue with a conditioning fat and milling saidmixture of plant residue and conditioning fat under reduced pressure,said conditioning fat being in a liquid state, the content of solvent inthe plant residue is reduced.

[0028] Further, by milling said mixture of plant residue andconditioning fat, said conditioning fat being in a liquid state, thesoil particles and hard plant parts are wetted thereby ensuring wetmilling conditions that reduce wearing of milling equipment.

[0029] By conducting the milling step at a temperature above 100° C. orby subjecting the resulting compound mixture to a post heat treatment atsuch temperatures the content of solvent is further reduced and amicrobial quality of food grade standard is provided.

3. DETAILED DESCRIPTION

[0030] Milling Conditions

[0031] Milling of the mixture of solvent-extracted plant residue andconditioning fat can be carried out by any suitable wet milling methodknown in the art.

[0032] Especially suited for the present method are retention mills thatare known as one-step refiner/conch equipment in the art of chocolateproduction. An example is the Macintyre Refiner/Conch described in“Chocolate, Cocoa and Confectionery”, 3.Ed., Chapman & Hall, 1989,p.154.

[0033] The milling temperature at which said conditioning fat is presentin a liquid state depends on the conditioning fat used.

[0034] High temperature favours the removal of the solvent and reducesthe viscosity of the slurry. Too high temperatures, however, may resultin undesirable decomposition of components in the meal e.g. flavour,carbohydrates and proteins. Too low temperatures, on the other hand, mayresult in undesirably long milling times before reducing the amount ofresidual solvent to an acceptable level.

[0035] In a preferred embodiment, the milling is carried out at atemperature in the range 40 to 160° C., preferably 40 to 130° C., mostpreferred 60 to 80° C.

[0036] Milling of the mixture of solvent-extracted plant residue andconditioning fat is carried out under reduced pressure whereby it isensured that the solvent dissolved in the conditioning fat can be drivenoff from the said mixture. In a preferred embodiment, said milling iscarried out under a pressure below 40 mbar whereby removal of solvent isincreased.

[0037] Milling is carried out for a time period that is long enough toprovide a desired grinding fineness of the plant residue. A desiredgrinding fineness of the milled plant residue can be measured in manyways known in the art.

[0038] In one aspect, the grinding fineness correlates to the maximumparticle size and the particle size distribution that provides desiredflow properties that are suited for subsequent processing andapplication.

[0039] In another aspect, the grinding fineness correlates to themaximum particle size that provides an efficient release of solvent fromthe plant parts to the conditioning fat and thereby ensures asufficiently low amount of residual solvent left in the compoundmixture.

[0040] In a preferred embodiment, the milled plant residue has a meanparticle size below about 40 μm whereby the content of solvent isreduced. Typically, a maximum particle size of about 200 μm is obtainedunder these milling conditions.

[0041] The particle size and distribution of particle sizes obtainedduring a milling process can be determined in any suitable way thatprovides consistent measures reflecting the grinding fineness of theplant residue. Different methods may provide different results for thesame plant residue.

[0042] For the preferred embodiments of an ongoing milling process, themicrometric measurement method has been used in the determination ofgrinding fineness.

[0043] The particle-size distribution is preferably determined by theanalytical wet sieving method of USP 24, Method II.

[0044] Solvent

[0045] The solvents used to produce the solvent-extracted plant residueespecially include those solvents that are permitted for the productionof extracted food ingredients, e.g. methanol, ethanol, 2-propanol andhexane.

[0046] Generally, solvents can be in any suitable form e.g. in the formof pure solvent of a suitable grade with respect to the application ofthe solvent-extracted plant residue, or mixtures of solvents.

[0047] In a preferred embodiment, the solvent comprises hexane.

[0048] According to Codex Alimentarius, Vol.1A, 1995 hexane is to beregarded as a food additive, and the use is justified by the objectivesin section 3.2(d). Furthermore, hexane is in compliance with the“Carry-Over Principles”. It may be present in a food as an additive ifthe additive is permitted and the amount does not exceed the maximumadditive so permitted.

[0049] In Europe, hexane is permitted as a food additive. The permittedmaximum amount of hexane is 10 mg/kg according to Directive 881344/EEC.

[0050] Plant Parts and Plant Residue

[0051] Plant parts from which plant residues of reduced plant fats areproduced are known in the art.

[0052] Generally, they include plant parts used in processing ofvegetable oils and fats that can be utilised in e.g. food industry.Typical plant parts are oil seeds, beans and nuts, e.g. rapeseeds,soybeans and shea nuts.

[0053] Generally, oil or fats are recovered by expression from the plantparts. Subsequently, solvent extraction of the pressed plant residueproduces a solvent-extracted plant residue, e.g. the so-called meal,with a very low fat content. The processing is detailed in “Bailey'sIndustrial Oil and Fat Products”, 1982.

[0054] In a preferred embodiment, said plant parts comprises oil seeds,husks, hulls, beans, nuts and shells.

[0055] Generally, the amount of fat content of the solvent-extractedplant residue may vary.

[0056] In a preferred embodiment, the meal has a fat content of lessthan 1% by weight obtained by the processing of whole seeds, beans andnuts comprising husks, hulls, shells, etc.

[0057] Preferred solvent-extracted plant residues are those containingfunctional constituents. Examples include meal from cocoa beans(Theobroma cacao) containing aroma and colour. Other examples includemeal from flaxseeds (Lineum usitatissimus) that is a source of phenolicacids and dietary fibres of which one third is water-soluble mucilage.

[0058] Post Heat Treatment

[0059] For applications of the treated solvent-extracted plant residueas a food ingredient, it is desired and sometimes required by healthauthorities to reduce the amount of residual solvent even further, andalso to ensure a microbiological quality of food grade standard.

[0060] We have found that both these objectives can be achieved byheating the treated solvent-extracted plant residue to a temperatureabove about 100° C.

[0061] Accordingly, if the milling has taken place at a temperaturebelow about 100° C., the resulting compound mixture of milled plantresidue and conditioning fat should be subjected to a post heattreatment at temperatures above about 100° C.

[0062] Particularly suitable conditions for post heat treatment can beobtained by proper selection of temperature, pressure, and post heattreatment time.

[0063] Accordingly, in a preferred embodiment, a sufficient temperaturein said post heat treatment of the compound mixture is in the range of100 to 160° C., preferably 110 to 140° C., most preferred 120 to 130° C.

[0064] In another preferred embodiment, said post heat treatment of thecompound mixture is carried out below atmospheric pressure, preferablybelow 40 mbar.

[0065] In still another preferred embodiment, said post heat treatmentof the compound mixture is carried out over a time period of 1 to 12hours, preferably 2 to 8 hours, in particular about 4 hours.

[0066] Generally, the post heat treatment can be performed eitherimmediately following the milling process, or it can be performed at alater time e.g. in a situation where storing is required and storingconditions do not ensure maintaining the microbiological quality of thetreated product.

[0067] In a preferred embodiment, said post heat treatment of thecompound mixture is carried out immediately after preparation thereof,e.g. in a continuous process.

[0068] Conditioning Fat

[0069] Generally, the conditioning fat is used as milling liquid thatacts as a lubricant and carrier oil into which the solvent migrates fromthe solvent-extracted plant residue particles during milling.

[0070] Consequently, conditioning fat comprises fat that is able tobring the solvent-extracted plant residue into a condition where theresidual solvent can migrate into the conditioning fat. This can beobtained for conditioning fat being in a liquid state providing properdispersion of the solvent-extracted plant residue particles.

[0071] The conditioning fat is selected to have a melting point belowthe milling temperature.

[0072] The conditioning fat is further selected depending on theapplication.

[0073] In a preferred embodiment, said conditioning fat is aconfectionery fat, or a vegetable fat.

[0074] The amount of conditioning fat depends mainly on the amountrequired for the solvent-extracted plant residue to disperse therein andfor the solvent to migrate therein. A skilled person is able to adaptthe amounts required for a particular application.

[0075] In a preferred embodiment, said conditioning fat is in an amountof at least 30% by weight, preferably 40 to 70% by weight.

[0076] The type of conditioning fat is selected according to theapplication of the final compound mixture of milled plant residue andfat.

[0077] Concerning fats and applications a general reference is made to:Michael Bockisch “Fats and Oils Handbook”, AOCS Press, 1998, Chapter 6,Modification of Fats and Oils, p.446-613 that details the processing andcharacteristics of fats and the alternatives to cocoa butter areespecially referred to in section 6.2.3.5, p.501-507.

[0078] In a preferred embodiment for the invention the followingcharacteristics for the conditioning fat suited for the intended useare:

[0079] A. Confectionery Applications (i.e. Compounds, Moulds, Fillingsand Coatings)

[0080] Suitable conditioning fats have a melting behaviour similar tothat of cocoa butter (CBE, CBS) and the following typical values: Solidfat content according to IUPAC 2.150 at 20° C. 65-97%  25° C. 55-95% 30° C. 35-63%  35° C.  0-15%

[0081] B. Other Applications (i.e. Doughs, Cake Mixes, Cream Fillings,Spreads, Coatings and Extruded Cereals)

[0082] Suitable conditioning fats have a melting behaviour designed forthe application in question and the following typical values: Solid fatcontent according to IUPAC 2.150: at 20° C. 12-65%  25° C. 10-55%  30°C.  3-35%  35° C.  0-10%  40° C.  0-5%

[0083] Plant

[0084] Plants suitable for the treatment according to the inventioninclude any suitable oil-bearing plant from which its fats can beextracted by a suitable solvent.

[0085] In a preferred embodiment, said plant is a cocoa plant (Theobromacacao) or other genus or species of the Byttneriacea family.

[0086] In a preferred embodiment, said plant parts comprise shells ofcocoa beans.

[0087] In another preferred embodiment, said plant is a linseed (flax)plant (Lineum usitatissimus).

[0088] In a preferred embodiment, said plant parts comprise hulls offlaxseeds.

[0089] Apparatus

[0090] Generally, parts and units of equipment applicable to be used tocarry out the method according to the present invention are known in theart, see Bailey (1982) and Beckett (1999).

[0091] Consequently, an apparatus for carrying out the method accordingto the present invention should comprise:

[0092] (a) a mixer adapted for mixing said solvent-extracted plantresidue and a conditioning fat; and

[0093] (b) a mill adapted to grind said mixture of solvent-extractedplant residue and conditioning fat from (a), and

[0094] (c) heating means for providing said conditioning fat in a liquidstate,

[0095] the mixer and mill being adapted to operate under reducedpressure in an explosion-proof installation.

[0096] Preferably, the apparatus further comprises post treatmentheating means for heating said mixture of milled plant residue andconditioning fat under reduced pressure to reduce the content of solventto an acceptable level and provide a microbiological quality ofsubstantial food grade standard.

[0097] The removed solvent can be disposed of in various ways.

[0098] Preferably, the apparatus further comprises regeneration meansfor the solvent, in particular hexane, whereby exhaust gases arereturned to a regeneration unit and the solvent is regenerated.

[0099] The regenerated solvent is advantageously circulated to thesolvent-extraction unit for producing solvent-extracted plant residue.

[0100] Compound Mixture of Milled Solvent-Extracted Plant Residue andConditioning Fat

[0101] The product of the invention is a compound mixture of a milledsolvent-extracted plant residue and conditioning fat obtainable by thetreatment according to the method of the present invention.

[0102] Food Products

[0103] A compound mixture according to the present invention can be usedin various applications in the food industry.

[0104] Generally, the resulting compound mixture of milled solventextracted plant residue and conditioning fat can be used as aningredient in fat containing food. The application area is dependentupon the plant material and the type of conditioning fat used.

[0105] Consequently, in another aspect of the present invention there isprovided a food product comprising the compound mixture according to theinvention.

[0106] In preferred embodiments, the compound mixture comprises aconfectionery fat whereby confectionery food products are obtained.

[0107] In a preferred embodiment, the confectionery food product is inthe form of a substitute for chocolate or as a substitute for a compoundof cocoa powder and vegetable fat. For specific applications see Beckett(1999).

[0108] In another group of preferred embodiments, the compound mixturecomprises a plastified fat whereby a variety of fat containing foodproducts can be obtained.

[0109] In preferred embodiments, the compound mixture containing theplastified fat is an ingredient in a cake, a cream filling, a spread, orextruded cereals.

[0110] In a particularly preferred embodiment, the meal is originatingfrom cocoa. Consequently, the food product comprises a compound mixtureof milled solvent-extracted cocoa residue and conditioning fat that canbe used to substitute cocoa powder and all or part of the fat in thefood product.

[0111] In another preferred embodiment, the meal is originating fromflaxseed. Consequently, the food product comprises a compound mixture ofmilled solvent-extracted flax residue and conditioning fat that can beused to substitute other fibre-containing ingredients e.g. graham flourand all or part of the fat in the food product.

[0112] In yet another aspect of the present invention there is provideda feed comprising the compound mixture according to the invention.

4. PREFERRED EMBODIMENTS

[0113] In the following, by way of examples only, the invention isfurther disclosed with a more detailed description of preferredembodiments.

[0114] Method of Treating Solvent-Extracted Plant Residue

[0115] The following illustrates the processing steps of an embodimentof the method according to the present invention following the prior artof vegetable oil processing to produce a solvent-extracted meal.

[0116] The solvent-extracted meal of the prior art comprisescoarse-grained and hard plant residues including extraction solvent,microorganisms and particles of sand and other impurities.

[0117] Apparatus for Treating Solvent-Extracted Plant R sidu

[0118] An apparatus suited for carrying out the method of the presentinvention comprises:

[0119] A mixer comprising a closed, stainless steel tank equipped with astirrer. Further, the tank is preferably equipped with venting means forremoving evaporated gasses, in particular the solvent, e.g. hexane.

[0120] A retention mill, preferably a one-step refiner/conch equipment,specifically a Macintyre Chocolate System, see “Chocolate, Cocoa andConfectionery”, 3.Ed, Chapman & Hall, 1989, p. 154, which has beenadapted to operate under reduced pressure, e.g. below 40 mbar, byconnecting the inner drum of the mill to a vacuum pump.

[0121] Heating means for maintaining the conditioning fat in a liquidstate, e.g. a jacket with hot water or steam, or an electric heatingelement.

[0122] An inlet means for adding of meal and conditioning fat, herepreferably conditioning fat in liquid state, and output means fordischarging the treated product.

[0123] All parts and units of the apparatus are installed explosionproof.

[0124] In a particularly preferred embodiment, the apparatus furthercomprises a heating means for post heat treatment of the mixture ofmilled plant residue and conditioning fat in a tank. Here the mixture ofmilled plant residue and conditioning fat is subjected to heat underreduced pressure, preferably below 40 mbar. The heating means preferablycomprises a jacket with steam, or an electric heating element.

[0125] In a particularly preferred embodiment, the apparatus furthercomprises a solvent regenerator means for removing and collectingexhaust gasses, e.g. hexane, from the various units of the apparatus,and regenerating the solvent, e.g. hexane, in a regenerating unit.

[0126] The regenerated solvent is circulated to a solvent-extractionunit for producing solvent-extracted plant residue.

[0127] Determination of Particle Size and Particle-Size Distribution ina Milling Process

[0128] The particle size and distribution of particle sizes obtained inthe milling process can be determined in any suitable way that providesconsistent measures reflecting the grinding fineness of the plantresidue.

[0129] For the preferred embodiments of the milling process, thespecific methods used are illustrated in the following.

[0130] In the present method, micrometric measurement of the largestparticle of a mass of particles provides a rapid method of particle sizedetermination for the determination of grinding fineness in an ongoingmilling process.

[0131] The largest particle size is determined in a procedurecomprising:

[0132] (a) in a mortar, or equivalent thereof, thoroughly mixing a smallquantity of sample of the mass of particles with an equal amount ofparaffin oil;

[0133] (b) providing an aliquot of this mixture between theplane-parallel surfaces of a micrometer calliper; and

[0134] (c) measuring the distance between the anvil and the spindle ofsaid calliper.

[0135] The procedure provides reproducible values of grinding finenessbelow about 40 μm.

[0136] The particle size distribution was determined by analytical wetsieving according to USP 24, Method II. Suitable test equipment for thismethod comprises the ultrasonic-sieve apparatus, type USG from Retch(Haan, Germany) wherein hexane was used as sieving liquid. The particlesize determination was performed on a defatted sample that was providedby treating samples with hexane in a ratio 1:2 by weight at 50° C.

5. EXAMPLES

[0137] Embodiments of the invention are further illustrated by thefollowing examples that are illustrative and should not be taken aslimiting the scope of the present invention as defined in the claims.

Example 1

[0138] Reduction of the Hexane Content by Wet Milling of Cocoa Meal in aConfectionery Fat

[0139] A mixture of 20 kg meal obtained as the hexane extracted residuefrom whole cocoa beans and 20 kg CEBES 30-08 was prepared at 60° C.

[0140] CEBES 30-08 (CEBES is a trade mark of Aarhus Oliefabrik A/S) is aconfectionery fat of the CBS-type based on fractionated and hydrogenatedpalm kernel oil. It has the following specifications: Solid fat contentaccording to IUPAC 2.150: at 20° C. 94-97%  25° C. 87-91%  30° C. 40-48% 35° C.  0-5%

[0141] The mixture of cocoa meal and CEBES 30-08 was transferred to aMACINTYRE Laboratory A1, Chocolate Refiner/Conch milling equipment(Macintyre Chocolate Systems, UK). The mixture was processed underreduced atmospheric pressure at 60° C. until the compound mixture had agrinding fineness below 40 μm, determined by micrometric measurementsduring the milling process. The individual measured values were in therange 25-34 μm.

[0142] The analytical results were: a hexane content of 1240 ppm in themixture before milling and a hexane content of 110 ppm after milling.

Example 2

[0143] Post Heat Treatment for Reduction of the Hexane Content in aCompound Consisting of Milled Cocoa Meal and a Confectionery Fat

[0144] Preliminary lab-scale experiments indicated that the hexanecontent in a compound consisting of milled cocoa meal in a vegetable fatcould be reduced by a post heat treatment under vacuum at a temperatureabove 100° C. A temperature range of 120-130° C. was appropriate toreach a final hexane content of less than 10 ppm within 1 to 3 hours.

[0145] To verify the necessary processing time the following pilot-scaletest was performed:

[0146] The compound mixture of Example 1 was transferred to a vesselequipped with a stirrer and heating jacket. At 64° C., a referencesample was taken. After applying vacuum (below 40 mbar), the vessel washeated to reach a constant temperature of 120° C. in the compound and apressure of about 12 mbar.

[0147] At different time intervals samples were taken.

[0148] The hexane content in the samples was determined by GC headspaceanalysis.

[0149] The analytical results were as follows: Reference after 0 min at64° C. - 110 ppm hexane Sample after 90 min at 120° C. - 10 ppm - Sampleafter 150 min at 120° C. - 10 ppm -

[0150] This example clearly demonstrates that by applying thisembodiment of the invention, it is possible to reduce the hexane contentof a compound mixture of a milled solvent-extracted plant residue andconditioning fat to acceptable levels.

Example 3

[0151] Milling and Post Heat Treatment of Cocoa Meal in a ConfectioneryFat

[0152] The objective is to reduce the hexane content and extend the postheat treatment to include the improvement of the microbiological qualityof the compound mixture to food grade standards. This is exemplified inthe following pilot experiment.

[0153] 1. Solvent-extracted Plant Residue

[0154] A meal of processed whole raw cocoa beans was used. The meal hada hexane content of 2 200 ppm, and the following particle sizedistribution: Particle size Fraction Accumulated (mm) % by weight % byweight >1.00 14.4 14.4 0.50-1.00 24.4 38.8 0.40-0.50 10.6 49.4 0.13-0.4040.3 89.7 <0.13 10.3 100.0

[0155] 2. Conditioning Fat

[0156] SILKAO 95-38 (SILKAO is a trade mark of Aarhus Olie) is avegetable cocoa butter substitute (CBS) based on interesterified andhydrogenated lauric oil, and it has the following specifications: Solidfat content according to IUPAC 2.150 at 20° C. 78-84%  25° C. 53-59% 30° C. 24-30%  35° C.  0-4%

[0157] 3. Procedure

[0158] A 1:1 mixture of meal and conditioning fat was prepared. Millingand post heat treatment were performed as described in Examples 1 and 2.

[0159] 4. Results

[0160] The results are tabulated in the following. Post heat Post heatBefore After treatment treatment Parameter milling milling for 1 hourfor 4 hours Water (%) 6.1 2.5 0.17 0.1 Hexane (ppm) 1120 80 30 10 Totalplate count, 25° C. 550 1400 180 <10 Total plate count, 30° C. 1300 4700350 20 Yeast and moulds, PCU 930 70 <10 <10 Bacillus, PCU 600 1400 <100<100 Bac. Cer., PCU <100 <100 <100 <100 Clost. Sul., PCU <10 <10 <10 <10Anaerobic, PCU 400 4000 800 <100 Aerobic, PCU 200 5000 900 <100

[0161] 5. Conclusion

[0162] This example demonstrates that by extending the post heattreatment period at 120° C. it is possible to reduce the content ofhexane and water as well as the microbial activity of a compound mixtureaccording to the invention.

Example 4

[0163] Milling and Post Heat Treatment of Cocoa Meal in a Vegetable Fat

[0164] The pilot-scale experiment detailed in Example 3 was repeatedwith the use of a different conditioning fat.

[0165] VEGAO 73-02 (VEGAO is a trade mark of Aarhus Olie) was used asconditioning fat. The fat is a partially hydrogenated vegetable bakeryshortening, and it has the following specifications: Solid fat contentaccording to IUPAC 2.150: at 20° C. 24%  30° C.  9%  35° C.  3%

[0166] After milling and a post heat treatment for four hours at 120°C., the compound was plastified by a shortening process.

[0167] The apparatus used for the shortening process was a PilotPerfector, Type 3-57 (Gerstenberg & Agger, DK) equipped with threechilling tubes, each fitted with an intermediate crystalliser followedby a pin rotor machine. The temperature sequence used was the following:Inlet   50° C. Chilling tubes −15° C. Outlet +18° C.

[0168] Due to the melting behaviour of the conditioning fat this finalprocess is necessary for stabilising the mixture as it converts it fromsemi-liquid and inhomogeneous into a plastic and homogeneous paste.

[0169] This example demonstrates that a semi-liquid fat can be used asconditioning fat in the method of the invention.

Example 5

[0170] Milling and Post Heat Treatment of Flaxseed Meal in a VegetableFat

[0171] The pilot-scale experiment in Example 4 was repeated with the useof a meal obtained from solvent extracted flaxseed.

[0172] The processing parameters during milling and post heat treatmentwere as detailed in Example 3. No major differences were observed.

[0173] The results are tabulated in the following. Post heat Post heatBefore After treatment treatment Parameter milling milling for 1 hourfor 4 hours Water (%) — 1.18 0.14 0.07 Hexane (ppm) 130 50 10 10 Totalplate count — 3000 30 <10

[0174] Finally a shortening process as detailed in Example 4 plastifiedthe compound.

[0175] This example demonstrates that the method of the invention isapplicable to a meal originating from a plant different to cocoa.

Example 6

[0176] Use of a Cocoa Meal Compound in a Confectionery Product

[0177] The compound mixture from Example 3 was tested in the followingrecipe (in % by weight) for a dark type, chocolate-like, mouldingcompound: Cocoa meal compound (Ex. 3) 30.0% SILKAO 95-38 15.0% Skim milkpowder 6.0% Sugar 48.6% Lecithin 0.4% Flavour q.s.

[0178] The cocoa meal compound and SILKAO are melted and mixed with therest of the ingredients. The mixture is refined on rollers followed byconching and moulded into bars without tempering.

[0179] A reference was prepared by substituting the 30% cocoa mealcompound in the recipe with 15% cocoa powder and 15% SILKAO 95-38.

[0180] Concerning gloss, snap and melt down no significant differencebetween the two bars was observed.

[0181] This example demonstrates the use of a cocoa meal compoundmixture according to the invention in a confectionery application.

Example 7

[0182] Use of a Cocoa Meal Compound in a Bakery Product

[0183] The compound mixture from Example 4 was tested in a Havana cake(chocolate cake) recipe as described in the following: Test cake,Reference cake, Ingredients measures in g measures in g VEGAO 73-02 8501000 Cocoa meal compound, Ex. 4 300 — Sugar 1000 1000 Eggs 850 850 Wheatflour 1350 1350 Cocoa powder — 150 Vanilla sugar 50 50 Raising agents(E500, E503) 50 50 Buttermilk 750 750

[0184] The dough is prepared by mixing the fatty ingredient(s) withsugar at high speed to maximum volume. The eggs are added one by one.

[0185] The rest of the ingredients are added and medium-mixing speedmaintained until the dough is ready for baking.

[0186] Baking is done at 190° C. for one hour.

[0187] After cooling the test cake is coated with the cocoa mealcompound mixture according to the invention from Example 6. Likewise thereference cake is coated with the reference compound mixture fromExample 6.

[0188] In an organoleptic panel test both cakes passed.

[0189] This example demonstrates the use of a compound mixture of milledsolvent-extracted cocoa meal in vegetable fat according to the inventionin a food product.

Example 8

[0190] Us of a Flax Meal Compound in a Bakery Product

[0191] Due to the high content of dietary fibres in the meal fromflaxseed it can be used to fortify food.

[0192] The following recipe (in % by weight) exemplifies the use of thecompound mixture from Example 5 as an ingredient in a biscuit of thedigestive type: Flax meal compound (Ex. 5) 30.0% VEGAO 73-02 5.0% Sugar12.0% Wheat flour 44.0% Glucose syrup 2.0% Dried malt extract 0.5% Salt0.5% Water 6.0% Flavour q.s.

[0193] The volume of the biscuit can be increased by the addition of araising agent.

[0194] The ingredients are mixed on a planet mixer fitted with a doughhook. The biscuits are processed on a rotary moulder and baked at 200°C. for 12 min.

[0195] This example demonstrates the use of a compound mixture accordingto the invention based on a plant residue different from cocoa in a foodproduct.

1. A method of treating solvent-extracted plant residue, the methodcomprising (a) providing a plant residue of one or more plant parts witha reduced content of plant fats, the fats having been extracted by meansof a solvent for said plant fats; (b) mixing said solvent-extractedplant residue with a conditioning fat; (c) milling said mixture of plantresidue and conditioning fat under reduced pressure said conditioningfat being in a liquid state; and (d) if the milling has taken place at atemperature below about 100° C., subjecting the resulting compoundmixture of milled plant residue and conditioning fat to a post heattreatment at temperatures above about 100° C.
 2. The method according toclaim 1 wherein said milling is carried out at temperature in the rangeof 40 to 160° C., preferably 40 to 130° C., most preferred 60 to 80° C.3. The method according to claim 1 or 2 wherein said milling is carriedout under a pressure below 40 mbar.
 4. The method according to any oneof claims 1 to 3 wherein said milled plant residue has a mean particlesize below about 40 μm.
 5. The method according to any one of claims 1to 4 wherein said solvent comprises hexane.
 6. The method according toany one of claims 1 to 5 wherein said plant parts comprise oil seeds,husks, hulls, beans, nuts and shells.
 7. The method according to any oneof claims 1 to 6 comprising the step (d) wherein said post heattreatment of said compound mixture of milled plant residue andconditioning fat is in the range of 100 to 160° C., preferably 110 to140° C., most preferred 120 to 130° C.
 8. The method according to claim7 wherein said post heat treatment is carried out under vacuum,preferably at a pressure below 40 mbar.
 9. The method according to claim7 or 8 wherein said post heat treatment is carried out over a timeperiod of 1 to 12 hours, preferably 2 to 8 hours, most preferred about 4hours.
 10. The method according to any one of claims 7 to 9 wherein saidpost heat treatment is carried out immediately after the milling step(c).
 11. The method according to any one of claims 1 to 10 wherein saidconditioning fat is a confectionery fat or a vegetable fat.
 12. Themethod according to any one of claims 1 to 11 wherein said conditioningfat is in an amount of at least 30% by weight, preferably 40 to 70% byweight of the compound mixture.
 13. The method according to any one ofclaims 1 to 12 wherein said plant is a cocoa plant (Theobroma cacao) orother genus or species of the Byttneriacea family.
 14. The methodaccording to claim 13 wherein said plant parts comprise shells of cocoabeans.
 15. The method according to any one of claims 1 to 12 whereinsaid plant is a linseed (flax) plant (Lineum usitatissimus).
 16. Themethod according to claim 15 wherein said plant parts comprise hulls offlax seeds.
 17. A compound mixture comprising a milled solvent-extractedplant residue and conditioning fat obtainable by the treatment accordingto the method as defined in any one of claims 1-16.
 18. A food productcomprising the compound mixture defined in claim
 17. 19. The foodproduct according to claim 18 wherein the compound mixture comprises aconfectionery fat.
 20. The food product according to claim 19 in theform of a substitute for chocolate or a substitute for a compound ofcocoa powder and vegetable fat.
 21. The food product according to claim18 wherein the compound mixture comprises a plastified fat.
 22. The foodproduct according to claim 18 comprising a compound mixture of milledsolvent-extracted cocoa residue and conditioning fat.
 23. The foodproduct according to claim 18 comprising a compound mixture of milledsolvent-extracted flax residue and conditioning fat.
 24. A feedcomprising the compound mixture defined in claim 17.